Drill column clamping means



Aug. 30, 1932. D. c. KLAUSMEYER 1,875,017

DRILL COLUMN CLAMPING MEANS Filed March l2, 1929 4 Sheets-Sheet l Aug 30, 1932 I D. c. KLAUSMEYER 1,875,017

DRILL COLUMN CLAMPING MEANS Filed March l2. 1929 4 Sheets-Sheet 2 Aug. 30, 1932. D. c. KLAUSMEYER 1,875,017

l DRILL COLUMN CLAMPING' MEANS Filed March l2. 1929 4 Sheets-Sheet 5 4 Sheets-Sheet 4 @nvm/woz www D. C. KLAUSMEYER DRILL*v COLUMN GLAMPING MEANS Filed March 12. 1929 Aug. 30, 1932.

K @391g @1i/iomega Patented Aug. 30, 132

inra STATI-:s-

PATENT etnica I DAVID C. KLAI'ISMEYER, or CINCINNATI, oIIIo, AssIGNoR To 'Inn CINCINNATI BICK- Form Toon Co., or OAKLEY, CINCINNATI, oIIIo, A conroImTIoN or oIIIo DRILL COLUMN CLJIMPING MEANS Application filed Marchl 12, 1929.v Serial No. 346,462.

' This invention relatesto clampingV mechanisms such as maybe used'for` eXample,`to clamp a movable portion of a machine tool to a stationary portion thereof during a machining operation.

VAn object of this invention is to render available a new method of actuating a clamp, wherein an operator manually initiates a flow ofpower to an'impositive clamp actuating means, manually maintains said flow for an indefinite period during which the clamp actuating means is actuated and finally overcome by resistance, `and'in. which the flow of power is automatically .discontinued as soon as the operator ceases manually to maintain it continuous.

Another object of--this invention is to render availableV a power actuated clamping mechanism, embodying a manual control, andy so to construct and arrange the power means and the manual control therefor thatboth the clamp and the power means will -be protected aga-inst damage due to a continued application of power after the clamp has been fully closed or fully opened.

Another object ofthe invention is to proi vide a power actuated clamping mechanism in which the force capable of being transmitted to the clampv during the clamping action will be substantiallyless than the force capable of being transmitted thereto during an unclamping action, whereby the possibility of so tightly setting the clamp tha-t it cannot be opened by the power means is precluded.

A further object is toy provide a clamping mechanism and power actuating means therefor so constructedv and arranged Vthat the prime mover of said power actuated means mayv continue to operate after the clamping or unclamping action has been completed,

without injury to the clamp device, the clamp actuating mechanism or the primemover.

This invention also proposes so to construct a power actuated clamping means that the prime mover thereof may be rendered ineffective by a complete closing of the clamp; to provide a limit stop to arrest the movement of the clamp actuating means should v(by reason of wear or otherwise) the clamp fail to be tightened upon a normal actuation thereof, and to providea cushioning means to limit :the movement of the clamp actuating means in clamp opening movement.

Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings.

The objects of this invention have been attained by the provision of a clamp mechanism comprising a contractile and expansile element adapted to be actuated to effect clamping and unclamping action by forward and reverse movements of an oscillatory shaft. Other forms of clamp elements, however, may be employed. A reversible overload electric motor is connected with said shaft and the fiow of electric current to said motor, to effect forward and reverse rotation, is controlled by manually actuated switches which are so constructed as normally to open to break the circuit to said motor and which may be maintained closed, to permit a How of current to the motor, only by continuous action of an operator. The switches are preferably of the spring opening push-button type and immediately the operator removes his linger from the button the switch automatically opens and the flow of electric currentto the motor is discontinued. The motor is so wo-und and insulated as to be capable of being maintained under the influence of the electric current, while stalled, for a period of three minutes or more which is longer than an operator could hold the switch closed without experiencing eXtreme fatigue if not actual pain. In other words it would be im possible for the operator to hold the switch closed suiiiciently longto cause overheating or damage to the motor. v

Inasmuch as the action of the clamp is almost instantaneous (requiring in most instances less than asingle rotation of an actuating shaft) it will be perceived that the present arrangement affords an electrically lactuated clamping mechanism whichl will not be damaged by failure of the operator to turn off the moto-r after the clamp has been either opened or closed.

To insure that the power means will, at all times, be capable'of opening the clamp, after having previously closed it, this invention proposes to, embody in the power drive.,`be-

tween the motor and the clamp,'a slip-clutch adapted to transmita lsubstantially greater torque in clamp vopening-movement than in clamp closingmovement..k

To enable others, skilled in thei'artzse :Eully to apprehend the underlying features hereof that .they may embody the same in the various y wayscontemplated by--this-f invention-elrawj-v i ings depicting l a preferred typical construcstion have been annexed as a .partof this .dis-,

closure and, in such drawings, like'lcharacters ofl reference denote .corresponding parte.

through all the views, of which Figure-1 isV an elevational?viewfpartl;yin section, ,of a'. ,portion of a machine :tool em.-k bodying the" present limprovedl clamping. means/.SF-ig-Q'is a horizontal sectionaliview on theel-ine: 2 #2 of Figilf showing one form' Vof .connection between the; actuating motor and theiclamp actuating shaft latertobe re'- P ferredI to. Figi, is a' detail horizontal section;` on thef lines. 3-3 of xli"`ig..1. Figi." 41 dis aiviewsimilar to lFig; Qg-.bu't showing in. addi' tionteayielding-.abutment 7to fcushioniifthe* clamp t aetaiating. mechanism in its Eclamp openingmovement. Fig; :5; is viewisimi-z lar.fto-F.1g; .2 but showing 'as discriminate ing! slip 1eluteh; located.' between the actuating motori: and the" yClamp actuating ishaft.. Figa Glis' a vertical.- section: ontheflinei 6:-16 offFig:

5 'huirshowing, in addition,` adjusting means to varythe* tension on 'the detntfelements therebyto vary ythettorque adapted: to. be

transmitted: Fig.'7 is a sectionzi-su'b'stantially on the. line `'Zi-*Tof Fig; 16 and {Figz Bfis-a dia-i grammaticlayout of one -f'orm 4of electric reircuit radaptedf to efleetl rotation of the? clamp actuating motorV and showing cfalsothe Yseli' opening.l push+button switches` for! selectively so connecting-'- ther- .circuit-ato the" .motori astd effect; fior-ward orf :reverse rotationf thereof;

andi-.thereby closing-or opening= of they-clamp..

: element'. i

fill-1 for-nv of -theinvention is disclosed-as'comprisl inge-contractile? and.' expansile fclamp'element lx'in the-nature of' anzannularfsleeve, split. as atf2 and. adapted-tube contracted-to Cause-itsinner-fisurlace'to gripsthe-Louter-cylindrical sur-face` 41 fof a post: or. column.v 5;",1 thereby to lock the two elementsrtogether to'..preventf relativei *movement therebetweenif `rProjecting Ifrom' the clamp elementyat one side of-the splita; are ears 1- .6l within which isi journaled ayclarnp;1 aetuating sha-13157: "Complementat earsf8arealsoformed :on the clampwelement tlf at tlreo'ppo'site sideofsaid split.y 1 -Interime'di4:

atei-therears @the-shaft his providedwitliian eccentric. fp oI-'ti'tni 9 Surrounded; by a tst-rap 1.0 into which is threaded a dra'wfrboltfhl.whiehr projects. througlr one fof -tlrei ears-r-Sraduhas bolts .15 passing loosely through the ears 8. fand-'threadedirito theifears 6-y serve te limit y the-expansion oft the 1clamp elementf -A hand i lever 1 6 `liXe cl.t0 ,the draw bolt 11 may be uti- 'liszed' to rotate said bolt, which, through its threaded connection with the strap 10, will 1,875.01? v Y i medium of abushing 13 and thrust bearing 14. It-will readily be perceived that oscillation ofthe shaft 7 to the-position'shown in Fig. 3 will move the bolt axially and thereby ellect contraction ofthe cla-'mp elem-ent Land that..oseillation of the shatffrom-,that position will'permitgthe. elampielenient to open-'dueto the resiliency of the lmetal therein. Limit eflee-,tedl bytheuse o-ff.-a.wor-m..17 and a coeperating--f wor-m 1- wheeh `:or A. segment A18, theformer y,bein-g .-oonnected to 1 the motorv shaft 100 and @the .-latterlbeing iixedto the. shaft( The par-ts rare normally-sovl adjusted that, as y the eccentric/approachesits-:dead y.cen-ter position. as. shownfin Fig.. 3,- thef elampele-` vment will be tightlygrippedupen the member- Gandsetup a high resistance-which lwilLresult iny stall-ingfthegmotor- M-.. It for.'Y any reason,- such-fiom example las; because-ot wear-,- the eccentric should.passthroughJ Vits gdeadcenter. posit-ion?- withoutf .completely closing .the clamp-sabutm'ent-lsfnrevdedby@ a 'C2-Sine;- 20whichhouses thew-orm l17 and segment 18,-v w-ill-engage gthefpfortion-Zlfot thiesegment and prevent@ further rotation. ot the.. segment f and sha1-t7 also resulting-in stallinggofthe motor. 1 A. si milar.,abut-ment--22 .isadapted, tof engage a.A portion 23 of-v the segment-5,.uponycompleteopening-ofthe, elamp-whigc-h also-effects sta-ll.- mgiffthe 'motor-*91* :t e V As hereinbefora statedg athe motor-Meijs' so ing.maintained-under; the influence. of the electric :current-,f wl 1i-le-stalled,'4 :tor f af periodof? three: minutes Qr;-more,.\.-without -eausivng overheating;- or *damages-tto the-l motor. f @To insure:thatathedmotomwillinotibe maintained anders-ther influer-menor the-:electric current las ducts'theacurnentftothemotor 'tofefeet either.' forward. ori reverse frotationthereofisconl.

l. trolled by self lopening switches which may be maintained closedfonly by continuous action of anoperator.- Fig. 8`shows a .2i-phase v alternating current circuit suitable for selectively rotating the motor' M in forward and reverse directions to 'effect clamping and unclainping action of the clamp element AThis circuit includes three power lines L1,

,Y L2 Vand L3; three motor terminals T1, T2

and T3; a controller designatedy generally as D and comprising contactors C1 and C2 and miscellaneous other elements common to circuits ofthis nature. Inasmuch as this circuit is more or less conventional land the' structural details thereof, arenot claimed Vin this application, detailed description thereof ,is deemed unnecessary. Suffice it to say that the circuit is controlled by twoA push-button switches F and R normally maintained opened as by springs f and r but adapted to be closed, in opposition to the springs, by pressure on the butt-ons. l/Vhei the switch F is closed, power lines L1 and L2 are connected with the motor terminals T1 and T2 and the motor is rotated forwardlyy and the cla-mp is closed. Immediately the operator removes his finger vfrom the push button the spring f automatically 'o opens the switch and the circuit is broken.

The switch R acts in a similar manner to connect/the linefL1 to terminal T2.and line Y L2 to terminal T1 thus causing reverse rot-ationof the motor'and unclamping action ofA the clamp element. 'The third power line ,EL3 is connected directly to the motor terminal and does not go through the controller `Momentary closure of the circuits is suiiicient to effect clamping and unclamping action which results in stalling the motor but,

as hereinbefore stated, the motor M is so;

constructed that the operator could, if he were able, maintain the switch closed a relatively long period, say three minutes, without injury to the motor. Thus a'perfect safety device is provided.

Fig. 4 shows a modified construction inlcluding a yielding abutment 24 comprising :a spring pressed plunger carried by the casing 20 and adapted to engage the portion 23 of the segment 18 to cushion the contact of the segment with the casing in its unclamping movement.

Figs. 5, G and 7 show still another embodiment of the invention in which the motor is not stalled upon complete closing and opening of the clamp but is permitted to run until the operator removes his finger from the switch button. The clamp actuating shaft 7, however, is limited in its movements to complete clamp closing and clamp open'- ing positions as hereinbefore described. In this embodiment of the invention the worm 17 engages a complete circular worm-gear between which and the shaft 7 is inter- 17. The member B is provided with a series of radial perforations 26 in which are located a series of detents 27 which are normally pressed radially outward by means of'expansile springs 28, which are adjust- .able as to tension as will presently be de- These detents are shown in the` j form of hardened balls Vand they normally scribed.

engage an annular run-way affording two series of facets a and provided by the female member B. These facets are inclined in opposite directions and at difer-l ent angles to a radial line intersecting their point of connection at which point the balls v27 bear, under the action of the springs The facets a are disposed at a more acute angle to a radial line than are the facets b. Consequently it requires greater torque to compel the balls to climb the facets a than to climb the facets Z). As a result of this constructionthe device will transmit a greater torque without yielding in the one direction ...c

than in the other and yet, by virtue of the fact that the balls are normally seated in the pocketsV formed by the construction, the device is positive in action within certain limits and quite devoid of any tendency to.`

creep.

The device is so arranged that rotation of then member A in a clockwise direction (as viewedin Fig. 5)'effects a clamp closing Vmovement of the shaft 7 and rotation in thel opposite direction effects an unclamping action. It will therefore be apparent that a substantially grea'ter torque will be transmitted to the shaft 7 to effect unclamping than to effect clamping. This insures against the clamp being so tightly set that the motor would be unable to release it.

Itis desirable to be able to adjust the pressure ofthe detent'balls against the raceway and,'inasmuch as there is a plurality of detents, it is desirable that the tension may be Vadjusted uniformly so that each will bear the saine load. This is accomplished by loeating a member 29 in the nature of a support for the inner end of each spring. The inember 29 may, to good advantage, be in the shape of a ball. These balls'are, in turn, supported by the conical face 30 of a collar P which is slidably mounted on the periphery of the hub 31 of the male member B.

Thesend.- oi the Y. collar.Y enters an annular Y groove vvhic'hji's .cut inthe outer '.fac'e Aof .the member BV and'intersectsthe radialqper-v e ;:Eo`rations`soV as to expose' theiballs'29 (and .enable their Aradialpositions, and therebythe' V`tension of: .the springsV .28,y to be determinedf, bylaxially shiftingthev kcollar P. The posiy ,-,.tionjof the collar is,'in turn, determined by f afnut 33 acting throughawaslier 34'; thenut Likewise a` 1. vyielding abutment V24,; is provided toy cushion the movement of the parts l.in clampy opening y .f l`movement These abntments are. adapted l' shaft'?.

tis to be understood that the torquetrans 1K mitted.fromthe-member A to thel member B isssnlficient to eiect closingsandopening of l' 25j Y tion of the shaft has been arrested,.either by the clamp elemental and thatafter therotar tightening ofthe .clamp `or bylcontact of the varm with-,either ot the abutments 19H01.' 24

' a-continued rotationof the worml'? bythe motor M will .'causethe ballsy 27 to ride'up Ithe faceted ory b, dependent upon the direction of rotationT andffthe'mernber AV may ycon- 4f-tinue to vrotaterelativetothe member B.

i il V- It will thus-r be seenthat thiseinvention is.

well adapted to accomplish the objects ennvvmerated in the foregoing.

Without-further analysisyrfthe foregoing j -l will so fully reveal the-.gist of theinvention vY lthatotherscan, by applying cn'rrentlrnowledge, readily adaptlitfor various utilizationsl`y by retaining one or more of the features-that,

, i from thefstandpointofthe priortart-,fairly `constitute essential characteristics of either,l

v thezgeneral or specilic Vaspects of this invenitionf and, thereforafsuchA adaptations. should -'.be,1fand .are intended to beK comprehended vwithin the fmeaning and range of equivalency 1.- of thefollowingclaimszf- ,-Having. 'thus revealed this invention, I claim as newand desirev tosecure theffol- Y 'lowing combinationsandelements, or eqnivf valents thereof',- by Letters:k PatentY ot Qllnite'd .1-. Aifclampingemechanism -fcombining a v y{irst .fiired...element; asecond contractile and a lynezaolv clampand then inthe `opposite;directien to means being adapted to be rendered inei'ec-- tive `Wlie-sailjeceentric element reaches approximatelyritszde'ad center positioni which it eiiv'ectjs clampingv oflsaid 'second element to.

L the movement otsaid clampactating means .should. the eccentric inadvertently "".pass through isaid Adead center `p0sition`;"and vreunclampingfmovement' "saidfirsft element; anemergency'stopvto arrest f -QfAffclamp mechanism. c 'lombiningwa first i fixed'element; a fsecond contractile and eX-f pansile elementiadapted to,eng'gage 'said fixed element gme'ans fto' cause contraction andi eX- c pansion of, the second'jelement, lsaid l' means includingV`v anleco'entric'! element Aoperatively vconnected .with the, second element; 'an oscil- ,i latoryfshaftfcarrying saideccentric element;A Y

power meansincluding fa reversible*electricv f motor and an electric cir'cuitembodyinggtwo Y self-opening push-button "switches adapted, l

when-.held closedfalternatelyby an operator, to :permit aviiow ofcnrrent 'to' ls aid-inotor to* .f eiectfvalternately; forward and `reverse rotation offs'aid mtorlandefltherebyjalternate .A kciampingand; unclamping movement of said clamp. .elementisaidf motor being' radapted to complete lclamping i and unclamping vof `said clamp. elementi andvbeing sowilred and insulated asa to ybe capableof remaining `under ont damage tothe motor.

the. .run neuen@ or :Said @umm while gstalled for a. period oithree'mifnutesl, with- In witness whereof, .I havehereuntofsubname...

expansile Velement.,-adaptedto :engageffsaid'I A 'ff'sxed element ;v means to cause ycontraction .ande y expansion of. the.: second zelement, said means e latory shaftcarryin'g said .-eccentr-ic;l element V-...power means including al reversiblefelectric f n; niotorfiand; anelectric.circuitaembodyingftwo including J an; eccentric s element.y operatively if econnectedigwithihe-secondfelement; an-oscil-` y `.-f seltopening :switches tooscillate sai'dfsliaft .y Gi-irstinggone direction 'to'` efectgclosing offsaid sllient mean'sfyieldlngly to*resist th'emove-y ment ofsaidiclampjactnatingmeans inits 

